The bones most commonly broken in human punch-ups also gained the most strength in early “hominin” evolution. They are also the bones that show most divergence between males and females.

Until recently, it was thought that the evolution in facial structure was tied to humans consuming tougher food, such as nuts and seeds.

But new research casts doubt on that belief, and a new paper by David Carrier, an evolutionary biologist at the University of Utah, claims our facial features firmed up because early man was repeatedly slugging other early man in the face.

Instead of diet, Prof Carrier and his co-author, physician Dr Michael Morgan, propose that violent competition demanded the development of these facial fortifications: what they call the “protective buttressing hypothesis”.

“Jaws are one of the most frequent bones to break – and it’s not the end of the world now, because we have surgeons, we have modern medicine,” Prof Carrier explained. “But four million years ago, if you broke your jaw, it was probably a fatal injury. You wouldn’t be able to chew food… You’d just starve to death.”

So, Australopithecus (predecessors to modern humans by about 3.5 million years), developed hearty bone structure around their eyes, jaws, cheeks and nose.

Now, it just serves the purpose of making you look like you need to be knocked down.